ML20099L572
| ML20099L572 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 11/20/1984 |
| From: | Crouse R TOLEDO EDISON CO. |
| To: | |
| Shared Package | |
| ML20099L567 | List: |
| References | |
| RTR-NUREG-0737, RTR-NUREG-737, TASK-2.B.1, TASK-TM TAC-56714, NUDOCS 8412010179 | |
| Download: ML20099L572 (4) | |
Text
APPLICATION FOR AMENDMENT TO FACILITY OPERATING LICENSE NO. NPF-3 FOR DAVIS-BESSE NUCLEAR POWER STATION UNIT NO. 1 Enclosed are forty-three (43) copies of the requested changes to the Davis-Besse Nuclear Power Station Unit No.1 Facility Operating License No. NPF-3, together with the Safety Evaluation for the requested change.
The proposed changes include Section 3.4.11, 4.4.11 and bases.
By /s/ R. P. Crouse Vice President, Nuclear Sworn and subscribed before me this 20th day of November,1984.
/s/ Laurio A. Ilinkle, nee (Brudzinski)
Notary Public State of Ohio My Commission Expires May 16, 1986 SEAL DbhK 0 he F
PDR J
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l Docket No. 50-346 License No. NPF-3 Serial No. 1102 November 20, 1984 Attachment I.
Changes to Davis-Besse Nuclear Power Station Unit 1, Appendix A Technical Specifications Section 3.4.11, 4.4.11 and Bases.
A.
Time required to Implement. This change is to be effective upon NRC approval.
B.
Reason for Change (Facility Change Request 84-145 Rev. B).
To provide Technical Specifications for the High Point vents which were installed per NUREG 0737 (Item II.B.1).
C.
Safety Evaluation (See Attached)
D.
Significant Hazard Consideration (See Attached)
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s Safety Evaluacion This amendment' request is to add Sections 3.4.11, 4.4.11 and Bases for the RCS high point vents and to-lock open valves RC 146 and RC 147 which are in series with the pressurizer vent valves RC 239A and RC 200 to the Technical Specifications.
The safety function of the RCS high point vents is to ensure proper cooling of the core by requiring operability of.the vents so that steam or non-condensable gas bubbles can be eliminated following the loss of natural circulation. The high point vents can be used to restore natural circulation or to enable system cooldown following an inadequate core cooling event.
The proposed amendment will be applicable only during Modes 1, 2 and 3 when the steam generators are required to provide the core cooling. There is no accident started in Mode 4 that would have a need for steam generator cooling or high point vents. Therefore, this system is not required to be operable during Mode 4.
NRC Generic Letter No. 83-37 requested that all pressurized water reactors include Technical Specifications requirement for the high point vents.
The high point vents have been installed at the top of the hot leg (one in each loop)_and on the pressurizer (in addition to the vent path through the PORV). ~Therefore, there are 3 vent paths. The Technical Specification will require that at least one vent path to be operable at each location during Modes 1, 2 and 3.
If there is no vent path operable at one of the locations, restore within 30 days or be in hot standby in 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and hot shutdown in 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
If there is no vent paths operable in 2 or all 3 locations, restore within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> or be in hot standby in 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> or hot shutdown in 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
The surveillance requirements ensure the operability of the vent paths and their associated valves. The vent path operability can be verified by either venting to the quench tank or bu injecting water into the reactor coolant system through the vents.
Valves RC 146 and RC 147 are in series with a. vent path in the pressurizer (downstream of valves RC 239A and RC 200) and shall be locked open to ensure operability of the associated vent path. Other manual valves in the high point vent system are already locked open.
It is concluded that the proposed amendment will adequately fulfill its intended safety function. Therefore no unreviewed safety questions involved.
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Significant Hazard Consideration t
This~ amendment request for the.High Point Vent. System does not represent a-
-Significant Hazard. The high point vents were installed-in accordance
.with NUREG 0737 (Item II.B.1) and requested Technical Specifications in -
Generic Letter No. 83-37.
The high point vents were installed after TMI to' vent noncondensible gases from the RCS which may inhibit core cooling during natural-circulation.
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The vents are located-on the top of the hot leg (one per loop) and the pressurizer. The pressurizer has two actual vent paths one_via the installed vent path and the other is the PORV. Either vent path can be
.t used.to satisfy the requirement of the high point vent for the pressurizer.
'The proposed amendment is applicable only during Modes 1, 2 and 3 when the steam eenerators are required to provide the core cooling. There is no accident starting in Mode'4 (as-requested in the Generic Letter 83-37) that would need a steam generator for cooling. Therefore, the vents are not required in Mode 4.
t The surveillance requirements ensure the operability of the vent path and the associated valves. Verification is accomplished by either venting to the quench tank or injection of water into the reactor coolant system through the vents.
The Commission has provided guidance concerning the application of the 3
standards in 10CFR50.92 by providing certain examples (48 FR 14870). One of the examples of actions involving no significant hazards considerations j
related to a change that constitutes an additional limitation, l
restriction, or control not presently included in the technical specifications:
for example, a 'more stringent surveillance requirement.
l (example 11) 1 The amendment request is an additional restriction not covered in present Technical Specification. The vent system was installed and the proposed Technical Specifications ensure the operability and actions requirements should a vent path become inoperable.
Based on the above information, this amendment request would not (1) involve a significant increase in the probability or consequences of an accident previously evaluated; or (2) create the possibility of a new or different kind of accident from any accident previously evaluated; or l
(3) involve a significant reduction in a margin of safety.
Therefore, based on the above and the Safety Evaluation, the requested License amendment does not present a Significant Hazard.
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